The tax was enforced by making the documents unenforceable in court if they had not been properly stamped.
In the case of parchment the stamp was first applied to paper which was attached to the document using glue and a tin metal strip.
[2] The use of the stamps in the United Kingdom was so successful that the same model was soon adopted in the rest of British Empire.
Operating like a meter franking machine, they are manufactured by many of the same companies, for instance Pitney Bowes and Neopost.
[3] Over-embossing dies may be confused with impressed duty stamps as they appear similar.
Often in red, they will usually include the date on the top and bottom of the die and are produced using the same method as impressed duty stamps.